Exact evaluation of maximal-ratio and equal-gain diversity receivers for M-ary QAM on Nakagami fading channels

Exact integral expressions are derived for calculating the symbol-error rat e (SER) of multilevel quadrature amplitude modulation (MQAM) in conjunction with L-fold antenna diversity on arbitrary Nakagami fading channel. Both m aximal-ratio combining (MRC) (in independent and correlated fading) and equ al-gain combining (EGC) predetection (in independent fading) diversity tech niques have been considered. Exact closed-form SER expressions for two rest ricted Nakagami fading cases (MRC reception) are also derived. An exact ana lysis of EGC for MQAM has not been reported previously, despite its practic al interest. Remarkably, the exact SER integrals can also be replaced by a finite-series approximation formula. A useful procedure for computing the c onfluent hypergeometric series is also presented.